Load transfer device



Patented Feb. 21, 1950 LoAp TRANSFER DEVICE Ray Cyr-.usi Romani. Lufkin, Tex., assignerI t- Texas Ifoiunries,l Ifnc., Lufkin, 'l3ex.,y a corpora-Y tion of Texas.`

Application March 16, 1945,', Serial No'. 583,0311

(Cl, MP8).l

9. Claims.

This invention relates. to load: transfer devices and; morer particularly tor devicesv for transferring loads between adjacent slabs of concrete or.- the like.

In. laying highways, runways, ramps. floors, etc., it is customary, to divide the concrete into individual slabs. The spaces or joints. between the slabs are lled with an ex-pansible` and compressible filler material and' the slabs are4 connected by dowels or like load transfer devices which extend across the jointsto transfer the-load from one slabto the other.

It is one of the objects ofthe presentv invention to provide a load; transfer device. which is extremely simple and inexpensive to construct and install and which eectively transfers loads from one slab. tothe other.

Another object is to.-A provide a load transfer device which will permit a limited longitudinal movement of the slab end-s. at the joint with.- out interfering with the transfer of the loads.

Still another object, is tov provide a load trans fer device which will limit the separation of the slabs at thev joint to prevent excessive opening up of the joint and loss. of* sealing contact between the ll'er and the. slab faces.

A still furtherA Objectis to provide a load transf fer device formed by identical members made up of rods or strips.

The above and other objects and advantages of the invention will be more readily apparent from the following description when read in connection with the accompanying drawing, in which- Figure 1 is a horizontal section looking from the bottom through a pair of slabs connected by the load transfer device of the invention;

Figure 2 is a vertical section on ther line 2.-2 of Figure 1;

Figure 3 is a perspective view of the load transfer device;

Figure Il` is a vertical section through an al-.y ternative construction;

Figure 5 is a. section on the line 5 5 of Fig-r ure'4; and

Figure 6 is a perspective view of the alternaE tive device.

As shown in Figures 1 and 2, a pair of ade jacent slabs ID and il of concrete or like Ina-.- terial are connected at a joint by an expansible ller I2 which engages the adjacent faces of the slabs to seal the joint therebetween. The ller l2 may be any desired type of material such as asphalt, compressed wood or metallic expansible filler strips.

To connect thev slabs for transfer Of loads therebetween a. pair ofload. transfer members which are substantially identical are mounted in theslabs respectively and interengage each. other in the spacebetween the slabs. Thememberaas shown, are formed of rods or wire bent intov a UShape to. provide legs.- I3. extending into. the slabs and. preferably turned; over at their ends as shown at |54; to anchor the members SQClllelY inthe slabs. 'lfheA ends of the members project beyond the slab.l facesr intoL the. joint space. between the slabs; and. are squeezed: together t0 form narrow.. tip portions t5. extending. at. right angles from thev plane ofl the; members The sides ofeach member are spaCed apart beyond the slab faces to leave openings through which the tip .portion of the, other member extends. When the load traIlSter device is installed in the slabs, theI members will connect together as ilT lustrated in Figures 1, 2 and 3; with each of the tip. portions I5: extending through the Opening provided by the opposite member. The. filler strip. i2 is preferably formed with openings through which the load transfer devices. may extend'.

In installing the load transfer devices in slabs, a series of devices are mounted atv spaced points along the joint between the slabs. Each Qi the devices is reversed with respect tol the adjacent devices. As seen in Figure 2, a vertical downward force on the slab Il will be transferred through the load transfer device to` the slab i0 due to. the bearing of the member carried by the slab. H on the cooperating member carriecl by the slab i0. In a similar mannerdownward forces on the slab ill will be transferred to the slab H through the adjacent load, transfer devices whose position is reversed relative to that illustrated. The devices may be of such size and so. spaced as to accommodate the max.- imum expected vertical loads on the slabs.

As the. .temperature Changes., the slabs tend. to expand or contract and. either to separate Q1. move closer together at the joints- The tip portions l5. of the lood transfer. members.. are S0 intorlooked .that they will limit. the permissible separation of the slabs at the J'Qfit so that the slab faces cannot separate far enough to move out of sealing, contact with the filler l2 In forming the joints, the 5111er is preferably made so that it. will, accommodate the maximum sxpeoterl .separation of the. slab faces and the load transferl members may be So instance that they willv permit the necessary degree of. separation but will engage each other to prevent excessive separation which might allow the joint to open up.

The tip portions I of the load transfer members are preferably coated with plastic material such as rubber, asphalt composition or the like as indicated at I5a. This material serves to locate the members properly relative to each other and to protect them against rust or corrosion. As the slabs expand or contract the plasticmaterial will be compressed between the two tip portions or between the tip portions and the slab faces to accommodate limited movement of the slab faces away from or toward each other as required. Preferably the coating is omitted from the surfaces which transmit vertical loads` rso that the relative Vertical positions of the slabs are xed.

Figures 4, 5 and 6 illustrate an alternative ,construction for connecting a pair of slabs I6 and |'I having a filler strip |8between their adjacent faces. The load transfer device illustrated in these figures is formed of a rod or wire-bent back on itself at its center to provide a relatively narrow tip portion |9. Just back of the tip portion the sides of the rod or wire are separated and bent laterally out of the plane of the member as indicated at 2| to provide an opening through the member which is offset from the tip portion I9.` Back of the separated portions 2| the sides of the rod are bent together again as indicated at 22 and terminate in projecting tips 23 to anchor the member in the slab.

In installing these devices in the slabs, the tip portion I9 of one member extends through the opening in the other member and into the opposite slab. The tip portions are greased or otherwise coated to prevent adhesion of the concrete thereto. The ends of the tip portions I9 are preferably coated with a plastic material such as rubber or asphalt composition as shown at 24 to yield when the tip portions tend to moveinto the slabs during expansion thereof. Also the offset sides 2| are similarly coated as indicated at 25 yieldingly to resist horizontal movement of the slabs in either direction and to assist in locating the members during installation. In addition, the 4coating 25 covers substantially the entire portion of the members which is exposed between the slabs to prevent rust or corrosion thereof.

When installed, the members will occupy the position indicated in Figures 4 and 5 sothat Vertical loads on `the slabs will be transferred through the members from one slab to the other. Whenthe slabs tend to separate due to contraction thereof, the tip portions I9 will slide through the openings to a limited extent but will eventually engage the separated portions 2| to prevent (further movement-of the slabs. This construction, therefore, operates in substantially the same manner 'as that of Figures 1 to 3 to transfer both vertical and horizontal forces between the slabs.

While two embodiments of the invention have been shown and described in detail, it will be understood that these are illustrative only and 'are not intended as a definition of the scope of the invention, reference being had for this purpose to the appended claims.

What is claimed is:

1. A load transfer device for use with adjacent slabs of concrete or the like comprising a pair of identical elongated members arranged in reversed relation and adapted to be imbedded in the slabs respectively throughout the major portion of theirl length with their end portions projecting beyond the slabs, the endportionof each 4 member being formed with an opening therethrough and with a reduced tip offset from the opening and of smaller horizontal section and extending through the opening in the other mem-A ber.

2. A load transfer device for use with adja` cent slabs of concrete or the like comprising a pair of identical members arranged in reversed relation and adapted to be imbedded in the slabs respectively with their end portions projecting beyond the slabs, the end portion of each member being formed with an opening therethrough and with a reduced tip of smaller horizontal section than the opening extending substantially at a right angle to the member and extending through the opening in the other member.

3. VA load transfer device for use with adjacent slabs of concrete or the like comprising a pair of identical elongated members arranged in reversed relation and adapted to be embedded in the slabs respectively throughout the major portion of their length with their end portions projecting beyond the slabs, the end portion of each member being formed with an opening therethrough and with a reduced tip lying substantially parallel to the member, the tip and the portion in which the .opening is formed being offset and the tip on each member extending through the opening in the other member.

4.' A load transfer device for use with adjacent slabs of concrete or the like comprising a pair of members adapted tobe imbedded in the slabs respectively, each member being formed of an elongated strip bent back on itself and adapted to have its end portions imbedded in one of the slabs and its central -portion'projecting from the slab, the central portion of each strip being spread apart to form an opening through the member and lying close together at the extreme outer end of the member to form a reduced tip, the tip on each member being smallerA than the opening and extending through the opening in the other member.

5. A loadtransfer device for use with adjacent slabs of concrete or the like comprising a pair of members adapted to be imbedded in the slabs respectively, each member being formed of. an elongated strip bent back on itself and adapted to have its end portions imbedded in one of the slabs and its central portion projecting from the slab, the central portions of the strip being spread apart toi form an opening throughl the member and lying close together at the extreme outer end of the memberk to form a reduced tip, the reduced tip on each member lying substantially at a right angle thereto and extending through the opening in the other member.

6. A load transfer device for use with adjacent Slabs of concrete or the like comprising'a pair of members adapted to be imbedded inthe slabs respectively, each member being formed of an elongated strip bentback on itself and `adapted to have its end portions imbedded in one of the slabs and its central. portion projecting from the slab, the central portions of the strip being spread apart .to formanv opening. through the member and lying close together at the extreme outer end of themember toform a reduced tip,V the reduced vtip on each member lying substantially parallel thereto and being'oifset from the spread portions of the strip and extending through the opening in the other member. l

'7. A load transfer device for use with adjacent slabs of concrete or ,the like comprising a pair of elongated members adapted to beimbedded the slabs respectively With their ends projecting beyond the slabs, the projecting end portion of each of the members being formed with an opening therethrough and with a reduced tip of smaller section than the opening extending substantially at a right angle to the member through the opening in the other member, and a coating of plastic material over the reduced tips.

9. A load transfer device for use with adjacent slabs of concrete or the like comprising a pair of elongated members adapted to be imbedded in the slabs respectively with their ends projecting beyond the slabs, the projecting end portion of each of the members being formed with an opening therethrough and with a reduced tipv lying substantially parallel to the member, the

tips and the portions in vwhich the openings arev formed lying at an angle and the tip on each member extending through the opening in the other member, the members being coated with plastic material adjacent the openings.

RAY CYRUS YEQMAN.

REFERENCES CITED The following references are of record in the file of this patent:

v UNITED STATES PATENTS Number Name Date 375,205 Sheldon Dec. 20, 1887 749,765 Wight Jan. 19, 1904 1,393,699 Purcell Oct. 11, 1921 l l 1,479,120 Warner Jan. 1, 1924: 1,780,588 Heltzel Nov. 4, 1930 2,103,894 Bussmann Dec. 28, 1937 2,125,857 Fischer Aug. 2, 1938 2,358,328 v I-Ieltzel Sept. 19, 1944 

